<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <title>运算</title>
    <link rel="stylesheet" href="css/04.css">
    <style>
    div {
        width: 100px;
        height: 100px;
        border: 1px solid #ccc;
    }
    </style>
</head>

<body>
    <div id="d1">div1</div>
</body>

</html>
